Ultrasonic surgical handpiece with torsional transducer

ABSTRACT

An ultrasonic surgical handpiece has a motor having a torsional transducer assembly along a central axis of the surgical handpiece, the motor being configured for operative connection to a power source. A surgical attachment has a proximal end detachably connected to the motor and a distal end defining a working plane for engagement with biological tissue. The motor is configured to create a standing wave along the central axis in response to the application of an electrical current and voltage from the power source. The standing wave defines an alternating pattern of nodes and anti-nodes along the central axis, wherein a position of one of the anti-nodes along the center axis corresponds with the position of the working plane.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Non-Provisional application claims priority to U.S. ProvisionalApplication Ser. No. 62/741,615 filed Oct. 5, 2018, the entiredisclosure of which is incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not applicable.

BACKGROUND

The present invention relates to an ultrasonic surgical device, and moreparticularly, the present invention relates to an ultrasonic surgicalhandpiece with a torsional transducer that creates a standing wave thatdefines an alternating pattern of nodes and anti-nodes along thehandpiece, with a position of an anti-node corresponding to a positionof a working plane that engages biological tissue.

Ultrasonic surgical devices are used in surgical procedures for variousapplications, such as, dissection, aspiration, coagulation, and cuttingof biological tissue. Typically, ultrasonic surgical devices usepiezoelectric transducers to operate as a half-wavelength resonator bygenerating a high frequency wave oscillation that vibrates varioussurgical tools at a resonant frequency. Generally, resonance can bedefined as the time harmonic exchange of the strain energy of thedistributed elasticity with the motional energy of the movement of astructure's distributed elasticity. The vibration may be longitudinal,radial, flexural, torsional or a combination of such forms of vibration.For purposes of physical analysis, such vibration can be mathematicallyrepresented as a standing wave which itself is composed of two waves ofeither strain or motion, with each of the two waves, either of strain ormotion, superimposed upon the structure, each traveling in the oppositedirection from the other, resulting in the formation of points of nomotion and maximum strain (nodes) and of maximum motion and minimum orvanishing strain (anti-nodes).

Compared to traditional surgical tools and techniques, ultrasonicsurgical devices provide numerous advantages. For example, ultrasonicvibration provides more precise cutting and better coagulation of thetissue than electro-surgical instruments, thereby reducing bleeding andreduced damage to surrounding tissue. In addition, ultrasonic vibrationprovides for less thermal damage, such as charring, and less desiccationthan cryogenic or electro-surgical instruments.

However, the advantages of ultrasonic surgical devices are limited bytheir use of so-called longitudinal vibration where the transducersgenerate vibration in an axial direction along the axis of the device.Accordingly, longitudinal vibration of the transducers moves thesurgical tool reciprocally in an axial direction, which still limits theprecision of the surgical tools during surgical procedures and createssignificant thermal energy that may damage surrounding tissue. Inaddition, longitudinal vibration causes cavitation of the irrigationfluid typically used in surgical procedures, which obscures the field ofvision during surgical procedures.

In comparison, torsional movement of the surgical tip provides smootherand more precise control, leading to less damage to the surroundingtissue. In addition, torsional movement creates less thermal energyresulting in decreased thermal damage to surrounding tissue. Also,torsional movement reduces the cavitation of irrigating fluid resultingin an improved field of vision during surgical procedures.

Therefore, there is a need for an ultrasonic surgical handpiece using atorsional transducer to provide more precise and efficient operation.

BRIEF DESCRIPTION

In one embodiment, a surgical handpiece includes a motor having atorsional transducer assembly along a central axis of the surgicalhandpiece. The motor is configured for operative connection to a powersource. A surgical attachment has a proximal end detachably connected tothe motor and a distal end defining a working plane for engagement withbiological tissue. The motor is configured to create a standing wavealong the central axis in response to the application of an electricalcurrent and voltage from the power source. The standing wave defining analternating pattern of nodes and anti-nodes along the central axis. Aposition of one of the anti-nodes along the center axis corresponds withthe position of the working plane.

In another embodiment, a surgical handpiece includes a plurality oftorsional transducers along a central axis of the surgical handpiece.The plurality of torsional transducers are configured for operativeconnection to a power source. A surgical attachment has a proximal enddetachably connected to the plurality of torsional transducers and adistal end defining a working plane for engagement with biologicaltissue. The plurality of torsional transducers are configured to createa standing wave along the central axis in response to the application ofan electrical current and voltage from the power source. The standingwave defines an alternating pattern of nodes and anti-nodes along thecentral axis. A position of one of the anti-nodes along the center axiscorresponds with the position of the working plane.

In another embodiment, a method of operating a surgical handpieceincludes providing a motor having a torsional transducer assembly alonga central axis of the surgical handpiece and a surgical attachmenthaving a proximal end detachably connected to the motor and a distal enddefining a working plane for engagement with biological tissue. Electricpower is provided to the motor, and a standing wave is formed definingan alternating pattern of nodes and anti-nodes along the central axis,wherein a position of one of the anti-nodes along the central axiscorresponds with the position of the working plane.

BRIEF DESCRIPTION OF THE DRAWINGS

The present inventive subject matter will be better understood fromreading the following description of non-limiting embodiments, withreference to the attached drawings, wherein below:

FIG. 1 is a perspective view of an ultrasonic surgical systemconstructed in accordance with an embodiment;

FIG. 2 is a cross-section view of the ultrasonic surgical handpiece withhousing removed taken along section A-A shown in FIG. 1 and acorresponding schematic illustrating a standing wave along theultrasonic surgical handpiece in accordance with an embodiment;

FIG. 3 is a perspective view of an ultrasonic tip in accordance with anembodiment;

FIG. 4 is an end view of the ultrasonic tip illustrating torsionalmotion at a working plane in accordance with an embodiment;

FIG. 5 is a partially exploded perspective view of an ultrasonicsurgical handpiece with a housing removed and a connection assembly inaccordance with an embodiment;

FIG. 6 is a cross-section view of the ultrasonic surgical handpiecetaken along section A-A shown in FIG. 1;

FIG. 7 is an exploded perspective view of a motor and surgicalattachment of the ultrasonic surgical handpiece in accordance with anembodiment;

FIG. 8 is a side view of a motor;

FIG. 9 is a cross-section view of the motor taken along section B-Bshown in FIG. 8; and

FIG. 10 is a cross-section view of the motor taken along section C-Cshown in FIG. 8.

Corresponding reference numerals indicate corresponding parts throughoutthe several figures of the drawings.

DETAILED DESCRIPTION

The following detailed description illustrates the inventive subjectmatter by way of example and not by way of limitation. The descriptionenables one of ordinary skill in the art to make and use the inventivesubject matter, describes several embodiments of the inventive subjectmatter, as well as adaptations, variations, alternatives, and uses ofthe inventive subject matter. Additionally, it is to be understood thatthe inventive subject matter is not limited in its application to thedetails of construction and the arrangements of components set forth inthe following description or illustrated in the drawings. The inventivesubject matter is capable of other embodiments and of being practiced orbeing carried out in various ways. Also, it is to be understood that thephraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting on all embodiments ofthe inventive subject matter.

The terminology used herein is for the purpose of describing particularexemplary embodiments only and is not intended to be limiting. As usedherein, the singular forms “a”, “an” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The steps, processes, and operations described herein are notto be construed as necessarily requiring their respective performance inthe particular order discussed or illustrated, unless specificallyidentified as a preferred order of performance. It is also to beunderstood that additional or alternative steps may be employed.

Embodiments described herein include ultrasonic surgical systems thathave control systems, surgical handpieces, motors, and surgicalattachments used in surgical procedures to engage biological tissue. Forexample, the ultrasonic surgical system may have a surgical handpiecewith a motor having a torsional transducer assembly. The torsionaltransducer assembly may have a variety of configurations as set forthherein. For example, the transducer assembly may be configured to createa standing wave along the central axis of the surgical handpiece inresponse to the application of an electrical current and voltage from apower source or control system. The standing wave may define analternating pattern of nodes and anti-nodes along the central axis witha position of one of the anti-nodes corresponds with the position of aworking plane of a surgical attachment that engages biological tissue,including both soft and hard tissue. The surgical attachment may have avariety of configurations as set forth herein. Optionally, theultrasonic surgical system may include an irrigation assembly and/or anaspiration assembly to irrigate and/or aspirate the biological tissue.

FIG. 1 is a perspective view of an ultrasonic surgical system 10constructed in accordance with an embodiment that includes a surgicalhandpiece 12 having a distal end 13 operatively connected to a controlsystem 14 with a connection assembly 16. In an exemplary embodiment, thecontrol system 14 is configured to provide power, irrigation fluid, andsuction or aspiration at a working plane 18 of a proximal end 15 of thehandpiece 12 during a surgical procedure. The working plane 18 of thehandpiece 12 may engage biological tissue 20 at a surgical site 22 toperform various surgical procedures, such as, cutting coagulation,irrigation, and aspiration. In alternate embodiments, the handpiece 12may be configured to engage soft biological tissue, such as, musculartissue, connective tissue, nervous tissue, epithelial tissue, and thelike, or hard biological tissue, such as, bone, enamel, dentin,cementum, and the like.

FIG. 2 is a cross-section view of the ultrasonic surgical handpiece 12with housing removed taken along section A-A shown in FIG. 1 and acorresponding schematic illustrating the standing wave 100 along theultrasonic surgical handpiece 12 in accordance with an embodiment. Inresponse to the application of electrical current and voltage from thecontrol system 14, the handpiece 12 creates a standing wave 100 alongthe central axis A with an alternating pattern of nodes 102 andanti-nodes 104 located at various positions along the central axis A.The X-axis of the schematic illustrates the position of the nodes 102and anti-nodes along the central axis A of the handpiece 12. The Y-axisillustrates the amplitude of the standing wave 100 along the centralaxis A of the handpiece 12.

For example, anti-nodes 104 are located a proximal end 284 of aconnector block 202, at an interface 150 between a first stack 212 and asecond stack 214 of a transducer assembly 210, an interface 152 betweenan amplifier 206 and a surgical attachment 300, an interface 154 betweenan angled adapter 302 and an ultrasonic tip 304, and at the workingplane 18. For example, the distance between anti-nodes 14 along thehandpiece 12 are (from distal end to the proximal end) about 0.903″inches, about 0.5922″ inches, about 0.658″ inches, about 1.087″ inches,about 1.057″ inches, about 1.66″ inches, about 1.626″ inches, and about1.365″ inches. For example, the amplitude of the standing wave 100progressively increases along the central axis A of the handpiece 12approaching the proximal end 15 of the handpiece 12, with the maximumamplitude being at the working plane 18.

Generally, the standing wave 100 may be described as a wave thatoscillates in time but whose peak amplitude profile does not move inspace. The standing wave 100 may represent the distribution of motionalong the length of the surgical handpiece 12 whose amplitude variesharmonically in time but remains spatially stationary. The peakamplitude of the wave oscillations at any point in space is constant intime, and the oscillations at different points throughout the wave arein phase with each other. The standing wave pattern defines analternating pattern of nodal positions, such as nodes and anti-nodes.When a standing wave is established, the nodes and anti-nodes remainlocated at the same position along the medium. A node of the standingwave is a location at which the amplitude of the standing wave isminimum, which may include zero. At the nodes, there is minimal to nodisplacement during each vibrational cycle. The standing wave 100 may beformed by the interference of two traveling waves. Therefore, nodes areproduced at locations where destructive interference occurs. Ananti-node of the standing wave is a location at which the amplitude ofthe standing wave is maximum. At the anti-nodes, there is a maximumdisplacement during each vibrational cycle. The anti-node vibrates backand forth between a positive displacement and a negative displacement.Anti-nodes are produced at locations where constructive interferenceoccurs.

FIG. 3 is a perspective view of an ultrasonic tip 304 in accordance withan embodiment. FIG. 4 is an end view of the ultrasonic tip 304illustrating torsional motion at the working plane 18 in accordance withan embodiment. The standing wave 100 created along the handpiece 12results in torsional motion about the central axis A at the workingplane 18 of the surgical attachment 300. For example, the amplitude AAof the tip 304 at the working plane 18 may be a maximum of about 18 milspeak-to-peak (450 microns) with an operating resonance frequency ofabout 24500 to 25500 Hz. However, alternate embodiments may produceother amplitudes at the working plane 18 and/or with other operatingresonance frequencies.

Referring again to FIG. 1, the control system 14 includes a power source24 that provides electrical current and power to the handpiece 12 viathe connection assembly 16. For example, the handpiece 12 may have anoperating frequency in a range of 24500 to 25500 Hz and be driven by thecontrol system 14 with power in a range of 85 to 110 watts. In alternateembodiments, the handpiece 12 may have an operating frequency of lessthan 24500 Hz or greater than 25500 Hz and be driven with power of lessthan 85 watts or greater than 110 watts.

An exemplary embodiment of the control system 14 also includes anirrigation fluid source 26 configured to provide irrigation fluid to thehandpiece 12 via the connection assembly 16. In one embodiment, thehandpiece 12 may be configured to communicate irrigation fluid throughone or more irrigation channels of the handpiece 12 to the working plane18 and the surgical site 22 for use as a cooling medium and irrigation.For example, the irrigation fluid source 26 may include an irrigationpump (not shown), such as a peristaltic pump, configured to pump waterfrom a water source to the handpiece 12 via the connection assembly 16.

In addition, an exemplary embodiment of the control system 14 includesan aspiration collector 28 to provide suction to the handpiece 12 viathe connection assembly 16. In one embodiment, the handpiece 12 may beconfigured to provide suction through a suction channel of the handpiece12 to the working plane 18 and the surgical site 22 for use asaspiration. For example, the aspiration collector 28 may include avacuum pump (not shown), configured to create a vacuum to the handpiecevia the connection assembly 16 to communicate aspirated biologicaltissue from the working plane 18 and surgical site 22 to a biologicalwaste cannister (not shown).

In the illustrated embodiment, the connection assembly 16 includes anelectrical connection 30 that transmits electrical power from the powersource 24 of the control system 14 to the handpiece 12. For example, theelectrical connection 30 includes an electrical cable 32 having aproximal end 34 coupled with the handpiece 12, and an electricalconnector 36 attached to a distal end 38 of the cable 32. Optionally, astrain relief 40 is attached at a cable end 42 of the electricalconnector 36. As illustrated, the electrical connector 36 is ahigh-voltage modular connector, such as, a connector manufactured byLEMO, that detachably connects with the control system 14. However, inalternate embodiments, the connector may be any suitable connectorcapable of operatively connecting with the control system 14.

The connection assembly 16 also includes an irrigation connection 44that transmits irrigation fluid from the irrigation fluid source 26 ofthe control system 14 to the handpiece 12. For example, the irrigationconnection includes a tube 46 having a distal end 48 connected to thecontrol system 14 and a proximal end 50 coupled with the handpiece 12,such as with an irrigation barb 52 (FIG. 5).

The connection assembly 16 also includes an aspiration connection 74that transmits aspirated material from the handpiece 12 to the aspiratorcollector 28 of the control system 14. For example, the aspiratorconnection 74 includes a tube 76 having a distal end 78 connected to thecontrol system 14 and a proximal end 80 coupled with the handpiece 12,such as with an aspiration barb 82 (FIG. 5).

In one or more embodiments, the irrigation barb 52 and/or the aspirationbarb 82 may be manufactured from any suitable material, including, butnot limited to, polymers, metals, metal alloys, any combination thereof.For example, irrigation barb 52 and/or the aspiration barb 82 may bemanufactured from titanium, a titanium alloy, aluminum, an aluminumalloy, copper, a copper alloy, iron, an iron alloy, nickel, a nickelalloy, silver, a silver alloy, cobalt, a cobalt alloy, tin, a tin alloy,gold, a gold alloy, tungsten, a tungsten alloy, beryllium, a berylliumalloy, platinum, a platinum alloy, chromium, a chromium alloy, lead, alead alloy, palladium, a palladium alloy, zinc, a zinc alloy, rhodium, arhodium alloy, niobium, a niobium alloy, vanadium, a vanadium alloy,manganese, a manganese alloy, indium, and indium alloy, tantalum, atantalum alloy, molybdenum, a molybdenum alloy, cadmium, a cadmiumalloy, thallium, a thallium alloy, ruthenium, a ruthenium alloy,iridium, an iridium alloy, gallium, a gallium alloy, osmium, an osmiumalloy, rhenium, a rhenium alloy, stainless steel, a brass, a bronze, aduralumin, or a nitinol. Illustratively, irrigation barb 52 and/or theaspiration barb 82 may be manufactured from an underdamped material, amaterial having a Q factor greater than 0.5, a metal alloy in anannealed condition, a titanium alloy in an annealed condition, or fromTi-6A1-4V extra-low interstitials in an annealed condition.

FIG. 5 is a partially exploded perspective view of the ultrasonicsurgical handpiece 12 with a housing 110 removed and a connectionassembly in accordance with an embodiment that includes a motor 200 anda surgical attachment 300. FIG. 6 is a cross-section view of theultrasonic surgical handpiece 12 taken along section A-A shown inFIG. 1. In an exemplary embodiment, the housing 110 includes an innersleeve 112, and outer sleeve 114, a collar 116, a nose cone 118, and anirrigation sleeve 120, that detachably assemble to receive the motor 200and the surgical attachment 300 and define an irrigation channel 122(FIG. 6) that communicates irrigation fluid from the irrigationconnection 44 to the working plane 18. For example, the generallycylindrical inner sleeve 112 includes a bore 124 configured to receivethe motor 200. The generally cylindrical outer sleeve 114 includes abore 126 configured to receive the inner sleeve 124 and motor 200 anddefines a portion of the generally annular irrigation channel 122between the inner sleeve 120 and the outer sleeve 122. The collar 116detachably couples with a distal end 128 of the outer sleeve 114, suchas with a threaded connection. The nosecone 118 includes a distal end130 configured to detachably couple, such as with a threaded connection,with a proximal end 132 of the outer sleeve 126 and define a portion ofthe irrigation channel 122. The irrigation sleeve 120 includes a distalend 134 configured to detachably couple, such as with a threadedconnection, with a proximal end 136 of the nosecone 118 and define aportion of the irrigation channel 122. A distal end 137 of theirrigation sleeve 120 defines an outlet 138 configured to directirrigation fluid from the irrigation channel 122 to the working plane 18and surgical site 22. In one or more embodiments, each component of thehousing 110 may be manufactured from any suitable material, including,but not limited to, polymers, metals, metal alloys, any combinationthereof.

FIG. 7 is an exploded perspective view of a motor 200 and surgicalattachment 300 of the ultrasonic surgical handpiece 12 in accordancewith an embodiment. In an exemplary embodiment, the surgical attachment300 includes an angled adaptor 302 and an ultrasonic tool or tip 304aligned along the central axis A of the handpiece 12. The angled adaptor302 includes a body 306 having a distal end 308 detachably connected tothe motor 200, such as with a threaded bore 310, and a proximal end 312detachably connected to the tip 304, such as with a threaded bore 314.The body 306 includes a distal portion 316 and a proximal portion 318offset from each other at angle at a junction 319, such as an angle inthe range of about 10°-45°, however, any angle can be used. The angledadaptor 302 may comprise an amplifier interface 320 at the distal end308, and angled tip interface 324 at the proximal end 312. In one ormore embodiments, angled adaptor 302 may comprise angled adaptor bore330 and a tip bore 332 (FIG. 6). As shown in FIG. 2, the junction 319 ispositioned to correlate with a node of the standing wave 100. Thecorrelation of the junction 319 with node 102 increases the amplitude ofthe standing wave 100 after the junction 319 as it approaches theworking plane 18.

In an exemplary embodiment, an ultrasonic tip 304 includes a body 334having a distal end 336 detachably connected to the proximal end 312 ofthe angled adaptor 302, such as with a threaded portion, and a proximalend 338 having a working plane 18 configured for engagement ofbiological tissue. The body 334 may include a plurality of portionshaving discretely different dimensions to correspond to the nodes 102and anti-nodes 104 of the standing wave. For example, the body 306 mayinclude a base portion 340 at the distal end 336, a tip portion 342 atthe proximal end 338, and a sloped intermediate portion 344 disposedbetween the base portion 340 and the tip portion 342. A bore 346 extendsthrough the length of body 334 along the center axis A. The ultrasonictip 304 is configured so that when the handpiece 12 is assembled, theposition of the working plane 18 corresponds to one of the anti-nodes104 of the standing wave 100.

In an exemplary embodiment, the ultrasonic tip may include a pluralityof teet configured to correspond with resonant frequencies as a functionof peak to peak amplitudes. In operation, the motion of the teethoverlaps each other peak to peak. The distance between the teethcorrespond to frequencies to produce 10-15 peak to peak amplitudes.

In alternate embodiments of the surgical attachment 300, the angledadaptor 302 and ultrasonic tip 304 may be configured using dimensionsthat correspond to position of the working plane 18 with an anti-node104 of the standing wave 100. For example, the ultrasonic tip 304 mayhave an overall length between distal end 316 and proximal end 318 in arange of about 2.9″ inches to about 3.1″ inches. The base portion 340may have a diameter in a range of about 0.2″ inches to about 0.3″inches. In alternate embodiments of the surgical attachment 300, theultrasonic tip 304 may be configured to accomplish various surgicalprocedures. For example, the ultrasonic tip 304 and in particular thetip portion 342 at the working plane 18 may be configured to engage softbiological tissue, such as, muscular tissue, connective tissue, nervoustissue, epithelial tissue, and the like, or hard biological tissue, suchas, bone, enamel, dentin, cementum, and the like.

In one or more embodiments, the angled adaptor 302 and/or the tip 304may be manufactured from any suitable material, including, but notlimited to, polymers, metals, metal alloys, any combination thereof. Forexample, angled adaptor 302 and/or the tip 304 may be manufactured fromtitanium, a titanium alloy, aluminum, an aluminum alloy, copper, acopper alloy, iron, an iron alloy, nickel, a nickel alloy, silver, asilver alloy, cobalt, a cobalt alloy, tin, a tin alloy, gold, a goldalloy, tungsten, a tungsten alloy, beryllium, a beryllium alloy,platinum, a platinum alloy, chromium, a chromium alloy, lead, a leadalloy, palladium, a palladium alloy, zinc, a zinc alloy, rhodium, arhodium alloy, niobium, a niobium alloy, vanadium, a vanadium alloy,manganese, a manganese alloy, indium, and indium alloy, tantalum, atantalum alloy, molybdenum, a molybdenum alloy, cadmium, a cadmiumalloy, thallium, a thallium alloy, ruthenium, a ruthenium alloy,iridium, an iridium alloy, gallium, a gallium alloy, osmium, an osmiumalloy, rhenium, a rhenium alloy, stainless steel, a brass, a bronze, aduralumin, or a nitinol. Illustratively, angled adaptor 302 and/or thetip 304 may be manufactured from an underdamped material, a materialhaving a Q factor greater than 0.5, a metal alloy in an annealedcondition, a titanium alloy in an annealed condition, or from Ti-6A1-4Vextra-low interstitials in an annealed condition.

FIG. 8 is a side view of the motor 200. FIG. 9 is a cross-section viewof the motor 200 taken along section B-B shown in FIG. 8. FIG. 10 is across-section view of the motor 200 taken along section C-C shown inFIG. 8. In an exemplary embodiment, the motor 200 includes a connectorblock 202 at a distal end 204, an amplifier 206 at a proximal end 208,and a transducer assembly 210 disposed between the connector block 202and the amplifier 206. The connector block 202, transducer assembly 210,and amplifier 206 are aligned along a central axis A of the handpiece 12and configured for operative connection to the power source 24 via theconnection assembly 16 (FIG. 1).

The transducer assembly 210 includes the first stack 212 and the secondstack 214 aligned along the center axis A in opposition to each otherabout interface 150 (FIG. 7). In the exemplary embodiment, the interface150 of the first stack 212 and second stack 214 correlates with theposition of an anti-node 104 (FIG. 2). The position of the stacks 212,214 relative to the nodes 102 and anti-nodes 104 place the stacks 212,214 within zones of minimal amplitude to reduce mechanical stress andpower loss on the transducer assembly 210.

The stacks 212, 214 are configured to operate or resonate as afull-wavelength resonator. Each stack 212, 214, includes a shaft or bolt216 configured to couple with a plurality of torsional transducers 218,a set of electrodes 220, and an inert ring 222 (FIG. 7). For example,the shaft 216 may include a raised collar 224 at a proximal end 226 toabut with the inert ring 222 with a pair of torsional transducers 218adjacent the inert ring 222. A distal end 228 of the first stack 212 isconnected to the connector block 202, and a distal end 230 of the secondstack 214 is connected to amplifier 206. A set of three electrodes 220are disposed between the components and operatively connected to thecontrol system 14 via the electrical connection 30 of the connectionassembly 16 (FIG. 1). An insulator sleeve 232 is disposed between theshaft 216, the torsional transducers 218, the electrodes 220, and theinert ring 222 to provide electrical insulation between the components.For example, the insulator 232 may be a generally cylindrical sleevecomprised of any suitable electrically insulating material, such as athermoplastic polymer material. When assembled, the transducer assemblyis placed under a predetermined amount of pre-stress to provide forproper interfacing between components. For example, the transducerassembly 210 is placed under a pre-stress in a range of about 1500-2500psi. In alternate embodiments, the transducer assembly 210 may includeany number of stacks of torsional transducers, including a single stack.

In the illustrated embodiment, each torsional transducer 218 is apiezoelectric ring configured to convert electrical energy intoultrasonic vibrations. Each transducer 218 includes a distal end surface234, and proximal end surface 236, a generally annular outer surface238, and a bore 240. The end surfaces 234, 236 may be generally smoothto increase the acoustic contact between transducers 218 when assembled.For example, the end surfaces 234, 236 may be absent of any coatings andpolished to a surface roughness in a range of about 2 Ra to 6 Ra. Inalternate embodiments, each ring may include a coating (not shown) onone or more of the surfaces with a predetermined thickness. The coatingmay be manufactured from an electrically conductive material, such as,aluminum, an aluminum alloy, silver, a silver alloy, copper, a copperalloy, gold, a gold alloy, platinum, a platinum alloy, tin, a tin alloy,palladium, a palladium alloy, nickel, a nickel alloy, beryllium, aberyllium alloy, tungsten, a tungsten alloy, a steel, chromium, achromium alloy, titanium, a titanium alloy, and the like.

The dimensions of the transducer 218 are predetermined to achieve theproper piezoelectrical effect. For example, the transducer 218 may havea thickness of about 0.145 to 0.215 inches. However, alternateembodiments may have a thickness of less than 0.145 inches or greaterthan 0.215 inches. For example, the transducer 218 may have an outerdiameter of about 0.465 to 0.655 inches. However, alternate embodimentsof may have an outer diameter of less than 0.465 inches or greater than0.655 inches. For example, the bore 240 of the transducer 218 may have adiameter of about 0.175 to 0.375 inches. However, alternate embodimentsmay have a diameter of less than 0.175 inches or greater than 0.375inches.

In an exemplary embodiment, one or more of the torsional transducers 218may be manufactured from a piezoelectric ceramic material, such as,perovskite material, a lead zirconate titanate (“PZT”) material,piezoxide material, a PXE 5 grade material, a PXE 52 grade material, aPXE 59 grade material, a PXE 21 grade material, a PXE 41 grade material,a PXE 42 grade material, a PXE 43 grade material, a PXE 71 gradematerial, and the like. Alternatively, each transducer may bemanufactured from a material having a crystal structure with no centerof symmetry, such as, a perovskite crystal structure. In one or moreembodiments, each torsional transducer 218 may be manufactured from amaterial having a tetragonal crystal lattice elementary cell below thematerial's Curie temperature, such as, a cubic crystal latticeelementary cell above the material's Curie temperature.

In an exemplary embodiment, the inert ring 222 includes a distal endsurface 242, and proximal end surface 244, a generally annular outersurface 246, and a bore 248. The dimensions and materials of thetransducer 218 are predetermined to achieve the proper configuration ofthe standing wave 100 along the central axis A, and correspondingly, theposition of the nodes 102 and anti-nodes 104. For example, the inertring 222 may have a thickness of about 0.265 to 0.385 inches. However,alternate embodiments may have a thickness of less than 0.265 inches orgreater than 0.385 inches. For example, the inert ring 222 may have anouter diameter of about 0.465 to 0.655 inches. However, alternateembodiments of may have an outer diameter of less than 0.465 inches orgreater than 0.655 inches. For example, the bore 248 of the inert ring222 may have a diameter of about 0.175 to 0.375 inches. However,alternate embodiments may have a diameter of less than 0.175 inches orgreater than 0.375 inches.

In one or more embodiments, the inert ring 222 may be manufactured fromany suitable material, including but not limited to, polymers, metals,metal alloys, etc., or from any combination of suitable materials. Forexample, the inert ring 222 may be manufactured from may be manufacturedfrom titanium, a titanium alloy, aluminum, an aluminum alloy, copper, acopper alloy, iron, an iron alloy, nickel, a nickel alloy, silver, asilver alloy, cobalt, a cobalt alloy, tin, a tin alloy, gold, a goldalloy, tungsten, a tungsten alloy, beryllium, a beryllium alloy,platinum, a platinum alloy, chromium, a chromium alloy, lead, a leadalloy, palladium, a palladium alloy, zinc, a zinc alloy, rhodium, arhodium alloy, niobium, a niobium alloy, vanadium, a vanadium alloy,manganese, a manganese alloy, indium, and indium alloy, tantalum, atantalum alloy, molybdenum, a molybdenum alloy, cadmium, a cadmiumalloy, thallium, a thallium alloy, ruthenium, a ruthenium alloy,iridium, an iridium alloy, gallium, a gallium alloy, osmium, an osmiumalloy, rhenium, a rhenium alloy, stainless steel, a brass, a bronze, aduralumin, or a nitinol. Illustratively, the inert ring 222 may bemanufactured from an underdamped material, a material having a Q factorgreater than 0.5, a metal alloy in an annealed condition, a titaniumalloy in an annealed condition, or from Ti-6A1-4V extra-lowinterstitials in an annealed condition.

In an exemplary embodiment, each electrode 220 is generally ring-shapedand includes a distal end surface 250, and proximal end surface 252, agenerally annular outer surface 254, and a bore 256. One or more of theelectrodes may include leads 258 that operatively connect to the controlsystem 14 via the electrical connection 30 of the connection assembly 16(FIG. 1). The dimensions of the transducer 218 are predetermined toachieve the proper connection between components. For example, theelectrode 220 may have a thickness of about 0.700 to 0.900 inches.However, alternate embodiments may have a thickness of less than 0.700inches or greater than 0.900 inches. For example, the electrode 220 mayhave an outer diameter of about 0.465 to 0.655 inches. However,alternate embodiments of may have an outer diameter of less than 0.465inches or greater than 0.655 inches. For example, the bore 256 of theelectrode 220 may have a diameter of about 0.175 to 0.375 inches.However, alternate embodiments may have a diameter of less than 0.175inches or greater than 0.375 inches. One or more of the electrodes 220may be manufactured from aluminum, an aluminum alloy, silver, a silveralloy, copper, a copper alloy, gold, a gold alloy, platinum, a platinumalloy, tin, a tin alloy, palladium, a palladium alloy, nickel, a nickelalloy, beryllium, a beryllium alloy, tungsten, a tungsten alloy, asteel, chromium, a chromium alloy, titanium, a titanium alloy, and thelike.

In an exemplary embodiment, the connector block 202 is a generallycylindrical component having a distal end 260 configured to detachablyconnect with the connection assembly 16 and a proximal end 262configured to couple with the transducer assembly 210. The outersurfaces 264 of the connector block 202 are configured to receiveO-rings that form a hermetic seal with the housing 110 (FIG. 5). Anaspiration bore 266 extends through the connector block 202 having aninlet 268 for coupling with the aspiration barb 82 at the distal end260, and an outlet 270 for coupling with a bore 290 of transducerassembly 210 at the proximal end 262. An irrigation bore 272 extendsthrough the connector block 202 having an inlet 274 for coupling withthe irrigation barb 52 at the distal end 260, and an outlet 276 forcoupling with the coupling with the irrigation channels 122 at theproximal end 262. The dimensions of the transducer 218 are predeterminedto achieve the proper configuration of the standing wave 100, andcorrespondingly, the position of the nodes 102 and anti-nodes 104.

In one or more embodiments, the connector block 202 may be manufacturedfrom any suitable material, including but not limited to, polymers,metals, metal alloys, etc., or from any combination of suitablematerials. For example, the connector block 202 may be manufactured frommay be manufactured from titanium, a titanium alloy, aluminum, analuminum alloy, copper, a copper alloy, iron, an iron alloy, nickel, anickel alloy, silver, a silver alloy, cobalt, a cobalt alloy, tin, a tinalloy, gold, a gold alloy, tungsten, a tungsten alloy, beryllium, aberyllium alloy, platinum, a platinum alloy, chromium, a chromium alloy,lead, a lead alloy, palladium, a palladium alloy, zinc, a zinc alloy,rhodium, a rhodium alloy, niobium, a niobium alloy, vanadium, a vanadiumalloy, manganese, a manganese alloy, indium, and indium alloy, tantalum,a tantalum alloy, molybdenum, a molybdenum alloy, cadmium, a cadmiumalloy, thallium, a thallium alloy, ruthenium, a ruthenium alloy,iridium, an iridium alloy, gallium, a gallium alloy, osmium, an osmiumalloy, rhenium, a rhenium alloy, stainless steel, a brass, a bronze, aduralumin, or a nitinol. Illustratively, the connector block 202 may bemanufactured from an underdamped material, a material having a Q factorgreater than 0.5, a metal alloy in an annealed condition, a titaniumalloy in an annealed condition, or from Ti-6A1-4V extra-lowinterstitials in an annealed condition.

In an exemplary embodiment, the amplifier 206 is a generally cylindricalcomponent having a proximal end 284 configured to detachably connectwith the surgical attachment 300 and a distal end 286 configured tocouple with the transducer assembly 210 (FIG. 5). The dimensions of theamplifier 206 are predetermined to achieve the proper configuration ofthe standing wave 100, and correspondingly, the position of the nodes102 and anti-nodes 104.

In one or more embodiments, the amplifier 206 may be manufactured fromany suitable material, including but not limited to, polymers, metals,metal alloys, etc., or from any combination of suitable materials. Forexample, the amplifier 206 may be manufactured from may be manufacturedfrom titanium, a titanium alloy, aluminum, an aluminum alloy, copper, acopper alloy, iron, an iron alloy, nickel, a nickel alloy, silver, asilver alloy, cobalt, a cobalt alloy, tin, a tin alloy, gold, a goldalloy, tungsten, a tungsten alloy, beryllium, a beryllium alloy,platinum, a platinum alloy, chromium, a chromium alloy, lead, a leadalloy, palladium, a palladium alloy, zinc, a zinc alloy, rhodium, arhodium alloy, niobium, a niobium alloy, vanadium, a vanadium alloy,manganese, a manganese alloy, indium, and indium alloy, tantalum, atantalum alloy, molybdenum, a molybdenum alloy, cadmium, a cadmiumalloy, thallium, a thallium alloy, ruthenium, a ruthenium alloy,iridium, an iridium alloy, gallium, a gallium alloy, osmium, an osmiumalloy, rhenium, a rhenium alloy, stainless steel, a brass, a bronze, aduralumin, or a nitinol. Illustratively, the amplifier 206 may bemanufactured from an underdamped material, a material having a Q factorgreater than 0.5, a metal alloy in an annealed condition, a titaniumalloy in an annealed condition, or from Ti-6A1-4V extra-lowinterstitials in an annealed condition.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the subject matterset forth herein without departing from its scope. While the dimensionsand types of materials described herein are intended to define theparameters of the disclosed subject matter, they are by no meanslimiting and are exemplary embodiments. Many other embodiments will beapparent to those of skill in the art upon reviewing the abovedescription. The scope of the subject matter described herein should,therefore, be determined with reference to the appended claims, alongwith the full scope of equivalents to which such claims are entitled. Inthe appended claims, the terms “including” and “in which” are used asthe plain-English equivalents of the respective terms “comprising” and“wherein.” Moreover, in the following claims, the terms “first,”“second,” and “third,” etc. are used merely as labels, and are notintended to impose numerical requirements on their objects. Further, thelimitations of the following claims are not written inmeans-plus-function format and are not intended to be interpreted basedon 35 U.S.C. § 112(f), unless and until such claim limitations expresslyuse the phrase “means for” followed by a statement of function void offurther structure.

As used herein, an element or step recited in the singular and proceededwith the word “a” or “an” should be understood as not excluding pluralof said elements or steps, unless such exclusion is explicitly stated.Furthermore, references to “one embodiment” of the presently describedsubject matter are not intended to be interpreted as excluding theexistence of additional embodiments that also incorporate the recitedfeatures. Moreover, unless explicitly stated to the contrary,embodiments “comprising” or “having” an element or a plurality ofelements having a particular property may include additional suchelements not having that property.

This written description uses examples to disclose several embodimentsof the subject matter set forth herein, including the best mode, andalso to enable a person of ordinary skill in the art to practice theembodiments of disclosed subject matter, including making and using thedevices or systems and performing the methods. The patentable scope ofthe subject matter described herein is defined by the claims, and mayinclude other examples that occur to those of ordinary skill in the art.Such other examples are intended to be within the scope of the claims ifthey have structural elements that do not differ from the literallanguage of the claims, or if they include equivalent structuralelements with insubstantial differences from the literal languages ofthe claims.

The foregoing description of certain embodiments of the presentinventive subject matter will be better understood when read inconjunction with the appended drawings. To the extent that the figuresillustrate diagrams of the functional blocks of various embodiments, thefunctional blocks are not necessarily indicative of the division betweenhardware circuitry. Thus, for example, one or more of the functionalblocks (for example, communication unit, control system, etc) may beimplemented in a single piece of hardware (for example, ageneral-purpose signal processor, microcontroller, random access memory,hard disk, and the like). Similarly, the programs may be stand-aloneprograms, may be incorporated as subroutines in an operating system, maybe functions in an installed software package, and the like. The variousembodiments are not limited to the arrangements and instrumentalityshown in the drawings.

Since certain changes may be made in the above-described systems andmethods, without departing from the spirit and scope of the inventivesubject matter herein involved, it is intended that all of the subjectmatter of the above description or shown in the accompanying drawingsshall be interpreted merely as examples illustrating the inventiveconcept herein and shall not be construed as limiting the inventivesubject matter.

Changes can be made in the above constructions without departing fromthe scope of the disclosure, it is intended that all matter contained inthe above description or shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

What is claimed is:
 1. A surgical handpiece, comprising: a motor havinga torsional transducer assembly along a central axis of the surgicalhandpiece, the motor being configured for operative connection to apower source; a surgical attachment having a proximal end detachablyconnected to the motor and a distal end defining a working plane forengagement with biological tissue; and wherein the motor is configuredto create a standing wave along the central axis in response to theapplication of an electrical current and voltage from the power source,the standing wave defining an alternating pattern of nodes andanti-nodes along the central axis, wherein a position of one of theanti-nodes along the center axis corresponds with the position of theworking plane.
 2. The surgical handpiece of claim 1, the surgicalattachment having a junction at a position that correlates with one ofthe nodes along the center axis to increase the amplitude of thestanding wave at the working plane.
 3. The surgical handpiece of claim1, the torsional transducer assembly having a plurality of torsionaltransducers, each torsional transducer having an end surface with asurface roughness configured for acoustic contact with an end surface ofanother torsional transducer.
 4. The surgical handpiece of claim 1, thetorsional transducer assembly having a plurality of torsionaltransducers configured to operate as a full-wavelength resonator alongthe central axis of the handpiece.
 5. The surgical handpiece of claim 1,wherein each torsional transducer comprises a piezoelectric ring.
 6. Thesurgical handpiece of claim 1, the torsional transducer assembly havinga first stack of torsional transducers and a second stack of torsionaltransducers opposed to each other about an interface, wherein theinterface correlates with the position of one of the anti-nodes.
 7. Thesurgical handpiece of claim 1, the surgical attachment comprising: anangled adaptor having a junction positioned to correspond with one ofthe nodes of the standing wave; and an ultrasonic tip having a workingplane positioned to correspond to one of the anti-nodes of the standingwave.
 8. The surgical handpiece of claim 1, the ultrasonic tip having aplurality of teeth configured to correspond with resonant frequencies asa function of peak to peak amplitudes.
 9. The surgical handpiece ofclaim 1, the motor further comprising: a connector block aligned alongthe central axis of the surgical handpiece; and an amplifier alignedalong the central axis of the surgical handpiece.
 10. A surgicalhandpiece, comprising: a plurality of torsional transducers along acentral axis of the surgical handpiece, the plurality of torsionaltransducers being configured for operative connection to a power source;a surgical attachment having a proximal end detachably connected to theplurality of torsional transducers and a distal end defining a workingplane for engagement with biological tissue; and wherein the pluralityof torsional transducers are configured to create a standing wave alongthe central axis in response to the application of an electrical currentand voltage from the power source, the standing wave defining analternating pattern of nodes and anti-nodes along the central axis,wherein a position of one of the anti-nodes along the center axiscorresponds with the position of the working plane.
 11. The surgicalhandpiece of claim 10, wherein each torsional transducer has an endsurface with a surface roughness configured for acoustic contact with anend surface of another torsional transducer.
 12. The surgical handpieceof claim 10, wherein the plurality of torsional transducers operate as afull-wavelength resonator along the central axis of the handpiece. 13.The surgical handpiece of claim 1, wherein each torsional transducercomprises a piezoelectric ring.
 14. The surgical handpiece of claim 10,the surgical attachment having a junction at a position that correlateswith one of the nodes along the center axis to increase the amplitude ofthe standing wave at the working plane.
 15. The surgical handpiece ofclaim 10, the surgical attachment comprising: an angled adaptor having ajunction positioned to correspond with one of the nodes of the standingwave; and an ultrasonic tip having a working plane positioned tocorrespond to one of the anti-nodes of the standing wave.
 16. Thesurgical handpiece of claim 10, the ultrasonic tip having a plurality ofteeth configured to correspond with resonant frequencies as a functionof peak to peak amplitudes.
 17. The surgical handpiece of claim 10,further comprising: a connector block aligned along the central axis ofthe surgical handpiece; and an amplifier aligned along the central axisof the surgical handpiece.
 18. A method of operating a surgicalhandpiece: providing a motor having a torsional transducer assemblyalong a central axis of the surgical handpiece; providing a surgicalattachment having a proximal end detachably connected to the motor and adistal end defining a working plane for engagement with biologicaltissue; and providing electric power to the motor; and forming astanding wave defining an alternating pattern of nodes and anti-nodesalong the central axis, wherein a position of one of the anti-nodesalong the central axis corresponds with the position of the workingplane.
 19. The method of operating a surgical handpiece of claim 18,further comprising: operating the plurality of torsional transducers asa full-wavelength resonator along the central axis of the handpiece. 20.The method of operating a surgical handpiece of claim 18, furthercomprising, oscillating an ultrasonic tip of the surgical attachment ina torsional motion about the central axis.